1. Field of the Invention
The present invention relates generally to a mobile terminal. More particularly, the present invention relates to a method and apparatus for video telephony in a mobile terminal and a method for correcting distortion during a video call.
2. Description of the Related Art
Video-enabled terminals are generally used by their users to perform audio and visual communication for transmitting and receiving images and voices through video and audio channels. Video telephony enables users of camera-equipped video terminals to see each other during phone conversations. Video telephony services can be provided through circuit-switching based on exchangers or through packet-switching over All-IP networks (IP for Internet Protocol). A video telephony service on a mobile communication network can be implemented, for example, according to the H.323 or H.324M recommendation from the International Telecommunications Union (ITU). H.323 is a system protocol for providing a video telephony service on a packet data network such as an IP-based network, H.324 is a system protocol for voice, video and data transmission over a public network, and H.324M (Mobile) is a version of H.324 adapted for mobile communication.
In audio/visual communication, typically comprising a conversation using a mobile terminal during a video call, the image of the user is captured by a camera unit of the mobile terminal and transmitted to the counterpart without image filtering.
FIG. 1 illustrates a video image of a user that is captured by a video-enabled mobile terminal for transmission during a conventional video call.
The image of FIG. 1 is one obtained in a usual manner through a self-shot function of the mobile terminal. As shown, the face image is enlarged and somewhat distorted. The reason for the enlarged and distorted image is that in order to obtain a natural looking face image during a video call, the user is inconvenienced by having to stretch an arm holding the mobile terminal to take a picture of his own face. Typically cameras are designed to be a minimum of about three feet or more from a subject, making the self-shot very difficult to obtain with good quality.